extjs4 Grid自动换行

var temp=Ext.create('Ext.grid.Panel', {

title: title.substring(0,10),

iconCls: 'icon-grid-list',

id:id,

forceFit: true,

region : 'center',

store: repStore,

columnLines:true,

closable:true,

columns: [{dataIndex:'usernam',text:'姓名',align:'center'},{dataIndex:'itemtypename',text:'类型',align:'center'},

{dataIndex:'itemcontent',text:'内容',width:500,renderer: function(value, meta, record) {

meta.style = 'overflow:auto;padding: 3px 6px;text-overflow: ellipsis;white-space: nowrap;white-space:normal;line-height:20px;';

return value;

}},{dataIndex:'itemstaname',text:'状态',align:'center'}]

});